## Sunday, August 23, 2015

### Betfair

While my daily approach to collecting odds seems to work fine with the bookmakers, it is a little problematic with betfair. The betfair odds bounce around a bit -- even from minute to minute -- and my point-in-time daily collection may not be that representative.

This morning at 8.39am the Coalition odds (unadjusted) were $1.55. When I looked at the graph, I thought I had got something wrong in my data collection or math. I rechecked the odds at 8.45am: The Coalition was on$1.70. It was the same again at 9am. To be fair, I noticed similar volatility when I wrote the code to extract the betfair odds. The difference between the two sets of odds were probabilities of 58.9 and 57.1 per cent. I will run with the two times out of three for this morning's chart. Even on these odds, this is the third daily movement in the Coalition's favour from betfair.

The only other movement today was Luxbet, which moved a touch in Labor's direction.

House Coalition Odds ($) Labor Odds ($) Coalition Win Probability (%)
2015-08-23 Betfair 1.67 2.22 57.069409
2015-08-23 CrownBet 1.65 2.25 57.692308